Category · 10 tips

Dart language

028Parse JSON safely with map patternsA switch on a map pattern checks keys and value types in one go, so bad JSON reaches your fallback case instead of a TypeError.json
024firstOrNull instead of try/catch on StateErrorfirst, firstWhere and single throw when nothing matches. The OrNull versions return null, and the type system makes you handle it.collections
021Skip nulls in collection literals with ...? and ?valueThe null-aware spread adds nothing for a null list, and a null-aware element leaves out a null entry, so you can drop the if (x != null).collections
019Extension types vs extension methodsAn extension method adds to a type. An extension type wraps it in a new static type, so a UserId can't be passed where an OrderId belongs.extension-types
016Await several futures with a record's .waitFuture.wait gives you a List of Object. A record of futures with .wait keeps each type and tells you which one failed.async
013Destructure lists with list patternsList patterns pull values out of a list by position, and a rest element skips or collects whatever sits in the middle.patterns
010Return multiple values with a recordA record returns two or more values without a throwaway class, and destructuring unpacks them in one line at the call site.records
008Switch on a record to match several values at oncePut two or three values in a record and switch on it. Each case is a row in a table, instead of a tangle of if/else.patterns
005A Result type with a sealed classReturn success or failure instead of throwing, and let an exhaustive switch make sure every caller handles both.sealed-classes
001Measure execution time with StopwatchDateTime.now() reads the wall clock, which can jump. Stopwatch can't, so use it to time code.performance